This invention relates to a body fluid absorbent panel suitable for use in a disposable body fluid absorbent wearing article such as a diaper or a sanitary napkin.
In conventional disposable diapers or sanitary napkins, it is well known to use, as a body fluid absorbent panel thereof, an assembly comprising a body fluid absorbent core formed by a mixture of hydrophilic fibers such as fluff pulp and high absorption polymer particles and covered with a liquid-pervious sheet or with such liquid-pervious sheet and a liquid-impervious sheet.
It is always desired for such a disposable body fluid absorbent wearing article such as a diaper or a sanitary napkin to improve a liquid absorbing capacity achieved by the article and, at the same time, to minimize its thickness. The requirements may be satisfied by increasing the quantity of high absorption polymer particles. However, the high absorption polymer particles have not the absorption rate as high as that achieved by the fluff pulp In addition, it becomes difficult to maintain the polymer in a constant shape and possibility that the polymer may leak out from the article as its quantity increases since the polymer is present in the form of particles. Upon moisture absorption, the high absorption polymer particles form a gel block which can no more absorb further quantity of moisture and, in consequence, the article often can not achieve the absorption expected on the basis of the quantity of the high absorption polymer particles used by the article
In view of the problem raised when a large quantity of the high absorption polymer particles are used, it is an object of this invention to provide a body fluid absorbent panel improved so that the problems can be overcome.
According to this invention, there is provided a body fluid absorbent panel comprising a core having upper and lower surfaces one of which is covered with a liquid-pervious sheet while the other of which is covered with a liquid-pervious or liquid-impervious sheet and hydrophilic fibers and high absorption polymer particles contained between the upper and lower surfaces.
The improvement according to this invention is in that the core contains heat-fusible fibers comprising the hydrophilic fibers or hydrophobic fibers and the entire fibers forming the core are put together to form a three dimensional network structure as the heat-fusible fibers are fused at least some of spots at which the entire fibers intersect the heat-fusible fibers wherein the polymer particles have an absorption rate less than 20 seconds as measured by Vortex method and are held within the network structure by held between respective pairs of the adjacent fibers forming the network structure or bonded to the fibers by means of binder.